So after a few years I am upgrading some of my stereo components and making some long over due changes. One of which is having a box built for a 12 under the drivers side to replace the ten that had no box. I also had a 12 under the observation seat that I will just be removing all together. So my question is will the one 12 be enough? Thanks!

my opinion...yes one well powered and set up sub is fine. i have pretty inexpensive polk dxi 124 dvc (12 inch) 360 rms / 720 watt peak in sealed box under observer seat. powered with alpine pdx-1.600m. It is awesome!

So after a few years I am upgrading some of my stereo components and making some long over due changes. One of which is having a box built for a 12 under the drivers side to replace the ten that had no box. I also had a 12 under the observation seat that I will just be removing all together. So my question is will the one 12 be enough? Thanks!

A single good subwoofer in the right enclosure, powered correctly, tuned properly, correctly loading into the cockpit, and in the best location is normally all it takes to satisfy a great majority of boat owners. Any secondary sub location is almost always a compromise, adds only a little output, but hurts the musicality. There are exceptions when the installation required a lot of custom boat modification. But if it's not a demo boat it's not necessary.